Although Mbuna and African Cichlids in general are very hearty fish, temperature will make a difference in more ways than you might know. Tropical temperatures for most fish usually range from around 76° to 80°, and some South American Cichlids are even found in much higher temperatures ranging from 81° to 85°. This is not the case for Mbuna or any other African Cichlids, so don't cook your fish!

African Cichlids, including your Mbuna should be kept right at 78° and never above 80° (if you can prevent it). The higher the temperature it is in your aquarium, the higher metabolism your fish will have. This means that your fish use more energy, in return they will eat more and expel more unwanted waste into the aquarium, it also means a shorter life and more irritable fish. Irritable fish means more aggressive fish which causes stress and in return, yes, more waste.

That is not the worst part of it though. Water's ability to hold oxygen is directly related to the temperature of the water. The colder the water, the more capable and efficient water is at holding precious oxygen for your fish. The warmer you keep your water, the less capable and efficient water is at holding precious oxygen for your fish. Each degree you raise the temperature, you diminish water's ability to hold oxygen.

I understand that in some cases your aquarium may run on the warm side, especially if you're using an acrylic aquarium. In this case don't worry about it, but try to keep the temperature from fluctuating too much (if you can prevent it). I recommend at least a 200 watt heater on a 60 Gallon Aquarium and a 300 watt heater on anything larger. I also recommend a good submersible, preferably one that "clicks" when you adjust it such as the Tetra - Acura submersible aquarium heaters.

Again don't cook your Africans but don't freeze them either. If you want healthy Mbuna, keep them at 78° and they will be happy. Happy fish are colorful fish. Last but not least, do not trust the setting on your heater, use a good glass mercury filled thermometer that sticks on the inside of your aquarium.